DeFelsko PosiTector 100 v.4.0 - Manual (Page 14)

Page 14 100 Series
Operation Overview
The Model 100 is an ultrasonic coating thickness Gage. As such it shares
characteristics with ultrasonic wall thickness gages and with magnetic and eddy
current coating thickness gages.
Like ultrasonic wall thickness gages, the Model 100 uses a transducer in the
probe to send pulses into the material to be measured and then measures the time
taken by that pulse to return to the probe tip. But unlike an ultrasonic wall
thickness gage the Model 100 is intended not to measure the total thickness of
the part but rather only the surface coating thicknesses. Thickness measurements
are therefore much smaller than those measured by ultrasonic wall thickness
gages. Secondly, the Model 100’s graphical representation of the echo returns
should not be confused with “A” scans presented by some wall thickness gages.
Like magnetic and eddy current coating thickness gages, the Model 100
measures the thickness of applied coatings. Where magnetic and eddy current
coating thickness gages measure the thickness of coatings over metal, the Model
100 is primarily intended to measure the thickness of coatings over non-metals.
It also has the additional capability of being able to measure the individual layer
thickness in a multi-layer coating system during a single measurement attempt.
Another difference: While the substrate plays a major roll in the operating
performance of magnetic and eddy current coating thickness gages, the coating
plays a relatively small roll. The opposite is true with the Model 100 because the
coating is the most important consideration when using the Gage and the
substrate is of relatively minor consequence.
It is always a good idea to verify that the Model 100 is operating properly before
measuring your application. This check makes sure the Gage has not been
damaged or altered in some way, perhaps by a previous user. There are a
number of ways to do this depending upon your requirements.
•
calibration ensures measurements are traceable to a national standard
(pg.24)
•
measure check standards at your work site (pg.44)
•
measure a known thickness of previously measured material
•
measure the included plastic shims (pg.28)
Before beginning any job be sure to check the settings found in
Setup q
q
Application Setup (pg.19) and alter them as necessary.